Libav
settb.c
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1 /*
2  * Copyright (c) 2010 Stefano Sabatini
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #include <inttypes.h>
27 #include <stdio.h>
28 
29 #include "libavutil/avstring.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/internal.h"
32 #include "libavutil/mathematics.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/rational.h"
35 #include "audio.h"
36 #include "avfilter.h"
37 #include "internal.h"
38 #include "video.h"
39 
40 static const char *const var_names[] = {
41  "E",
42  "PHI",
43  "PI",
44  "AVTB", /* default timebase 1/AV_TIME_BASE */
45  "intb", /* input timebase */
46  "sr", /* sample rate */
47  NULL
48 };
49 
50 enum var_name {
58 };
59 
60 typedef struct SetTBContext {
61  const AVClass *class;
62  char *tb_expr;
64 } SetTBContext;
65 
66 static int config_output_props(AVFilterLink *outlink)
67 {
68  AVFilterContext *ctx = outlink->src;
69  SetTBContext *settb = ctx->priv;
70  AVFilterLink *inlink = ctx->inputs[0];
71  AVRational time_base;
72  int ret;
73  double res;
74 
75  settb->var_values[VAR_E] = M_E;
76  settb->var_values[VAR_PHI] = M_PHI;
77  settb->var_values[VAR_PI] = M_PI;
79  settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
80  settb->var_values[VAR_SR] = inlink->sample_rate;
81 
82  outlink->w = inlink->w;
83  outlink->h = inlink->h;
84 
85  if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
86  NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
87  av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
88  return ret;
89  }
90  time_base = av_d2q(res, INT_MAX);
91  if (time_base.num <= 0 || time_base.den <= 0) {
92  av_log(ctx, AV_LOG_ERROR,
93  "Invalid non-positive values for the timebase num:%d or den:%d.\n",
94  time_base.num, time_base.den);
95  return AVERROR(EINVAL);
96  }
97 
98  outlink->time_base = time_base;
99  av_log(outlink->src, AV_LOG_VERBOSE, "tb:%d/%d -> tb:%d/%d\n",
100  inlink ->time_base.num, inlink ->time_base.den,
101  outlink->time_base.num, outlink->time_base.den);
102 
103  return 0;
104 }
105 
106 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
107 {
108  AVFilterContext *ctx = inlink->dst;
109  AVFilterLink *outlink = ctx->outputs[0];
110 
111  if (av_cmp_q(inlink->time_base, outlink->time_base)) {
112  int64_t orig_pts = frame->pts;
113  frame->pts = av_rescale_q(frame->pts, inlink->time_base, outlink->time_base);
114  av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
115  inlink ->time_base.num, inlink ->time_base.den, orig_pts,
116  outlink->time_base.num, outlink->time_base.den, frame->pts);
117  }
118 
119  return ff_filter_frame(outlink, frame);
120 }
121 
122 #define OFFSET(x) offsetof(SetTBContext, x)
123 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM
124 static const AVOption options[] = {
125  { "expr", "Expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, { .str = "intb" }, .flags = FLAGS },
126  { NULL },
127 };
128 
129 #if CONFIG_SETTB_FILTER
130 static const AVClass settb_class = {
131  .class_name = "settb",
132  .item_name = av_default_item_name,
133  .option = options,
134  .version = LIBAVUTIL_VERSION_INT,
135 };
136 
137 static const AVFilterPad avfilter_vf_settb_inputs[] = {
138  {
139  .name = "default",
140  .type = AVMEDIA_TYPE_VIDEO,
141  .get_video_buffer = ff_null_get_video_buffer,
142  .filter_frame = filter_frame,
143  },
144  { NULL }
145 };
146 
147 static const AVFilterPad avfilter_vf_settb_outputs[] = {
148  {
149  .name = "default",
150  .type = AVMEDIA_TYPE_VIDEO,
151  .config_props = config_output_props,
152  },
153  { NULL }
154 };
155 
156 AVFilter ff_vf_settb = {
157  .name = "settb",
158  .description = NULL_IF_CONFIG_SMALL("Set timebase for the video output link."),
159 
160  .priv_size = sizeof(SetTBContext),
161  .priv_class = &settb_class,
162 
163  .inputs = avfilter_vf_settb_inputs,
164 
165  .outputs = avfilter_vf_settb_outputs,
166 };
167 #endif /* CONFIG_SETTB_FILTER */
168 
169 #if CONFIG_ASETTB_FILTER
170 static const AVClass asettb_class = {
171  .class_name = "asettb",
172  .item_name = av_default_item_name,
173  .option = options,
174  .version = LIBAVUTIL_VERSION_INT,
175 };
176 
177 static const AVFilterPad avfilter_af_asettb_inputs[] = {
178  {
179  .name = "default",
180  .type = AVMEDIA_TYPE_AUDIO,
181  .get_audio_buffer = ff_null_get_audio_buffer,
182  .filter_frame = filter_frame,
183  },
184  { NULL }
185 };
186 
187 static const AVFilterPad avfilter_af_asettb_outputs[] = {
188  {
189  .name = "default",
190  .type = AVMEDIA_TYPE_AUDIO,
191  .config_props = config_output_props,
192  },
193  { NULL }
194 };
195 
196 AVFilter ff_af_asettb = {
197  .name = "asettb",
198  .description = NULL_IF_CONFIG_SMALL("Set timebase for the audio output link."),
199  .priv_size = sizeof(SetTBContext),
200  .inputs = avfilter_af_asettb_inputs,
201  .outputs = avfilter_af_asettb_outputs,
202  .priv_class = &asettb_class,
203 };
204 #endif /* CONFIG_ASETTB_FILTER */
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
Definition: settb.c:53
AVOption.
Definition: opt.h:234
static const AVFilterPad outputs[]
Definition: af_ashowinfo.c:232
Main libavfilter public API header.
static const char *const var_names[]
Definition: settb.c:40
int num
numerator
Definition: rational.h:44
AVFrame * ff_null_get_video_buffer(AVFilterLink *link, int w, int h)
Definition: video.c:30
static int av_cmp_q(AVRational a, AVRational b)
Compare two rationals.
Definition: rational.h:55
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: settb.c:106
Definition: settb.c:54
Definition: settb.c:52
char * tb_expr
Definition: settb.c:62
const char * name
Pad name.
Definition: internal.h:42
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:38
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:571
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:728
AVOptions.
static const AVOption options[]
Definition: settb.c:124
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:211
static double av_q2d(AVRational a)
Convert rational to double.
Definition: rational.h:69
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:139
static int config_output_props(AVFilterLink *outlink)
Definition: settb.c:66
A filter pad used for either input or output.
Definition: internal.h:36
#define FLAGS
Definition: settb.c:123
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:129
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:551
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define AVERROR(e)
Definition: error.h:43
#define OFFSET(x)
Definition: settb.c:122
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void * priv
private data for use by the filter
Definition: avfilter.h:584
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:144
Definition: settb.c:51
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:168
common internal API header
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:105
#define M_E
Definition: ratecontrol.c:39
Definition: settb.c:56
AVFrame * ff_null_get_audio_buffer(AVFilterLink *link, int nb_samples)
get_audio_buffer() handler for filters which simply pass audio along
Definition: audio.c:26
LIBAVUTIL_VERSION_INT
Definition: eval.c:55
NULL
Definition: eval.c:55
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:240
av_default_item_name
Definition: dnxhdenc.c:52
Describe the class of an AVClass context structure.
Definition: log.h:33
Filter definition.
Definition: avfilter.h:421
static const AVFilterPad inputs[]
Definition: af_ashowinfo.c:221
rational number numerator/denominator
Definition: rational.h:43
#define M_PHI
Definition: mathematics.h:34
const char * name
Filter name.
Definition: avfilter.h:425
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:578
rational numbers
int den
denominator
Definition: rational.h:45
Definition: settb.c:55
An instance of a filter.
Definition: avfilter.h:563
double var_values[VAR_VARS_NB]
Definition: settb.c:63
internal API functions
var_name
Definition: setpts.c:60
simple arithmetic expression evaluator